The Use of Sludge and Sulphide to Remove Heavy Metals from Sewages before Activated Sludge Treatment

1988 ◽  
Vol 20 (4-5) ◽  
pp. 285-292 ◽  
Author(s):  
István Licskó
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Sludge Treatment ◽  
Unit Costs ◽  
Sulphide Ions ◽  
Costs Of Treatment ◽  
Simple Phase ◽  
Plant Trials

The removal of five different heavy metals (Zn2+, Cu2+, Cr 3+,Cd 2+ and Ni 2+) was studied under laboratory conditions using close to neutral mixed municipal wastewater. 90 to 95 % of the Zn2+, Cu2+ and Cr3+ was found to precipitate within 5 min and to become removable by simple phase separation. The Cd2+ and Ni2+, however, refused to precipitate, unless a “reagent” (sulphide ion, primary and activated sludge) was added. In the presence of these, cadmium was normally more readily removed than nickel. Both heavy metals were removed most efficiently, when primary sludge (1.4 g.dm−3) and sulphide ions (5-15 mg.dm−3) were added in combination. As demonstrated by plant trials, this treatment would cause the heavy metals to precipitate and settle out in the primary settling tank, so that traces only would enter the aeration tank.The excess sludge would thus contain trace quantities of heavy metals only, removing an obstacle to land disposal. The introduction of this unit operation has been estimated to increase the overall construction and costs of sewage and sludge treatment by 2.3 %, the unit costs of treatment by 6 %.

scholarly journals Microalgae as biological treatment for municipal wastewater – effects on the sludge handling in a treatment plant

2018 ◽  
Vol 78 (3) ◽  
pp. 644-654 ◽  
Author(s):  
J. Olsson ◽  
S. Schwede ◽  
E. Nehrenheim ◽  
E. Thorin
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Waste Activated Sludge ◽  
Activated Sludge Process ◽  
Primary Sludge ◽  
Thermophilic Conditions ◽  
Mesophilic Conditions

Abstract A mix of microalgae and bacteria was cultivated on pre-sedimented municipal wastewater in a continuous operated microalgae-activated sludge process. The excess material from the process was co-digested with primary sludge in mesophilic and thermophilic conditions in semi-continuous mode (5 L digesters). Two reference digesters (5 L digesters) fed with waste-activated sludge (WAS) and primary sludge were operated in parallel. The methane yield was slightly reduced (≈10%) when the microalgal-bacterial substrate was used in place of the WAS in thermophilic conditions, but remained approximately similar in mesophilic conditions. The uptake of heavy metals was higher with the microalgal-bacterial substrate in comparison to the WAS, which resulted in higher levels of heavy metals in the digestates. The addition of microalgal-bacterial substrate enhanced the dewaterability in thermophilic conditions. Finally, excess heat can be recovered in both mesophilic and thermophilic conditions.

Fate of cerium dioxide (CeO2) nanoparticles in municipal wastewater during activated sludge treatment

2012 ◽  
Vol 108 ◽  
pp. 300-304 ◽  
Author(s):  
Francisco Gómez-Rivera ◽  
James A. Field ◽  
Dustin Brown ◽  
Reyes Sierra-Alvarez
Keyword(s):  
Activated Sludge ◽  
Cerium Dioxide ◽  
Municipal Wastewater ◽  
Ceo2 Nanoparticles ◽  
Sludge Treatment

scholarly journals Dewatering, Stabilization, and Final Disposal of Waste Activated Sludge in Constructed Wetlands

2021 ◽  
Vol 25 ◽  
Author(s):  
Alejandro Jorge Mariñelarena ◽  
Hugo Di Giorgi ◽  
Jorge Donadelli
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
National Park ◽  
Treatment Plant ◽  
Treatment Wetlands ◽  
Sludge Treatment ◽  
Environmentally Sustainable ◽  
Class A ◽  
Volatile Solids ◽  
Specific Oxygen Uptake Rate

Objective: This research aimed to assay the dehydration and stabilization of surplus biosolids from a wastewater activated sludge treatment plant, with sludge-treatment wetlands, at the Iguazú National Park (Misiones, Argentina). Materials and Methods: A 12-cell sludge-treatment reed beds (STRB) system was built and operated for four years. Afterwards, the accumulated sediments were analyzed for total solids (TS) concentration, volatile solids (VS) reduction, specific oxygen-uptake rate (SOUR), and heavy metals and pathogens concentrations. Results and Discussion: TS concentration increased from 0.55 % to 14.3 %, VS were reduced by 33.3 %, and SOUR lowered to 1.09 mg O2gTS-1 h-1. These figures and the final concentrations of heavy metals and pathogenic microorganisms (102 MPN E.coli.gTS-1) indicated a degree of stabilization and sanitation that allowed classifying these biosolids as Class A, according to the Argentine guidelines, National Resolution 410/18, and enabled their reuse for soil amendment in landscapes and other agronomic purposes. Conclusion: The technology tested showed good results applied under a tropical climate, with annual temperatures between 17 and 27 °C, rainfall of 1870 mm y-1, and planted with autochthonous vegetation. Furthermore, it allowed the reuse of 221 t (144 m3) of a harmless product in an environmentally sustainable way.

Occurrence of benzothiazoles in municipal wastewater and their fate in biological treatment

2004 ◽  
Vol 50 (5) ◽  
pp. 203-208 ◽  
Author(s):  
A. Kloepfer ◽  
R. Gnirss ◽  
M. Jekel ◽  
T. Reemtsma
Keyword(s):  
Activated Sludge ◽  
Sulfonic Acid ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Total Concentration ◽  
Sewage Treatment ◽  
Liquid Chromatography Mass Spectrometry ◽  
Sludge Treatment ◽  
Conventional Activated Sludge ◽  
The Individual

A number of 2-substituted benzothiazoles that are known to be used as fungicides, corrosion inhibitors and vulcanization accelerators in industry have been analyzed in municipal wastewater and the effluents of activated sludge and membrane bioreactor (MBR) treatment over a three month period. All six analytes were regularly detected in the municipal wastewater by liquid chromatography-mass spectrometry and amount to a total concentration of 3.4 μg/L. Of these compounds benzothiazole-2-sulfonic acid (1,700 ng/L), benzothiazole (850 ng/L) and 2-hydroxybenzothiazole (500 ng/L) were most prominent. The source of the benzothiazole emission is yet unknown. Activated sludge treatment did not reduce total benzothiazole concentration significantly. Removals of the individual compounds ranged from 90% for 2-mercaptobenzothiazole and 70% for hydroxybenzothiazole to 40% for benzothiazole. The concentration of benzothiazole-2-sulfonic acid increased by 20%, whereas 2-methylthiobenzothiazole increased by 160% during activated sludge treatment, likely due to the methylation of mercaptobenzothiazole. Total benzothiazole removal in two parallely operated MBRs was significantly better (43%) than in the conventional activated sludge treatment. Namely benzothiazole and benzothiazole-2-sulfonic acid were more effectively removed. This first systematic study on the occurrence of benzothiazoles in municipal wastewater has shown that this is a relevant class of trace contaminants in municipal wastewater which is only incompletely removed in biological wastewater treatment. Emission from sewage treatment is dominated by the most polar benzothiazole-2-sulfonic acid. MBR treatment may reduce but cannot avoid this emission.

Effects of the membrane technology of the dimensioning of municipal wastewater treatment plants

1998 ◽  
Vol 38 (3) ◽  
pp. 173-178
Author(s):  
A. Seyfried ◽  
E. Dorgeloh ◽  
E. Brands ◽  
P. Ohle
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Lower Energy ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Solids Retention ◽  
Municipal Wastewater Treatment Plants

The successful application of membrane filtration on the activated sludge process is a recent development. Two processes are most common: separate modules and submerged modules, with the former being the more promising due to the lower energy consumption. While they allow high sludge ages, conventional sludge ages are equally viable, thus allowing the use of tested and reliable dimensioning techniques. The near perfect solids retention of the membrane filtration, however, can lead to problems with the accumulation of inert solids and heavy metals in the activated sludge. In that area, further research is necessary to develop safe dimensioning methods.

Source characterization and removal of N-nitrosamine precursors during activated sludge treatment

2020 ◽  
Vol 6 (9) ◽  
pp. 2432-2443
Author(s):  
Xiaolu Zhang ◽  
Daekyun Kim ◽  
David L. Freedman ◽  
Tanju Karanfil
Keyword(s):  
Water Quality ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Source Water ◽  
Source Characterization ◽  
Sludge Treatment ◽  
Potential Source ◽  
Source Water Quality

Municipal wastewater discharges after secondary biological treatment (e.g., the activated sludge (AS) process) are a major potential source of N-nitrosamine precursors which may impact downstream source water quality.

Potential fertilizing properties of sewage sludge treated in the sludge treatment reed beds (STRB)

2013 ◽  
Vol 68 (6) ◽  
pp. 1412-1418 ◽  
Author(s):  
Katarzyna Kołecka ◽  
Hanna Obarska-Pempkowiak
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Sewage Sludge ◽  
Municipal Wastewater ◽  
Residual Fraction ◽  
Municipal Wastewater Treatment ◽  
High Concentration ◽  
Nitrogen And Phosphorus ◽  
Sludge Treatment ◽  
Reed Beds

In previous research the fertilizer value of sludge from reed beds was evaluated based on the sampling sludge on different depths from four Danish sludge treatment reed beds (STRB) after long periods of stabilization. The dewatering efficiency of sewage sludge in the STRB is comparable to mechanical dewatering. The long-term stabilization of sewage sludge progressively decreases the concentration of organic matter due to the process of humification. The aim of the work was to determine the changes of organic matter concentration, nutrients concentrations as well as speciation of selected heavy metals (Cd, Pb, Ni, Cr, Cu and Zn) in vertical profile of the sewage sludge stabilized in the STRB for 7–15 years. The analyzed sewage sludge was collected from the STRB treating sludge from four municipal wastewater treatment plants located in Denmark serving from 9,000 to 40,000 person equivalent. Analyzed heavy metals (except for Zn) were mostly bound with the most stable – residual – fraction. The most stable metals were Pb and Cr, where the share of the residual fraction exceeded 80.0%. The most mobile metal was Zn, where the share of the mobile fractions (calculated as the sum of I, II and III fractions) exceeded 85.0%. The high concentration of nitrogen and phosphorus is the decisive factor in the high valuation of sludge stabilized in the STRB as fertilizer.

REMOVAL OF HEAVY METALS IN ACTIVATED SLUDGE TREATMENT SYSTEMS

1987 ◽  
Vol 60 (1-6) ◽  
pp. 79-99 ◽  
Author(s):  
DONALD B. AULENBACH ◽  
MICHAEL A. MEYER ◽  
EILEEN BECKWITH ◽  
SHRIKANT JOSHI ◽  
CHITTIBABU VASUDEVAN ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Sludge Treatment ◽  
Removal Of Heavy Metals
Sign in / Sign up

Export Citation Format

Share Document